Answer:

Explanation:
The Hi line of the Balmer series is emitted in the transition from n = 3 to n = 2 i.e.
and 
The wavelength of Hi line of the Balmer series is given by :




So, the wavelength for this line is 550 nm. Hence, this is the required solution.
No because an atom consists of <u>two</u> main parts <em>and</em> <u>three</u> subatomic particles - protons, neutrons, electrons. Each one is smaller than an atom, therefore they are subatomic particles. An atom only requires protons and electrons to be an atom - e.g. Hydrogen has 1 proton and 1 electron. Neutrons do not affect the overall charge of the atom, and only increase the atomic mass.
Answer:
Tech B is correct and Tech A is incorrect.
Explanation:
Here Tech A is wrong because when diagnosing an overheating hydraulic system, it is not necessary to un plugg the oil cooler rather it should be plugged to for proper diagnosis.
Technician B says running the hydraulic system at a lower operating temperature will reduce the possibly of oil oxidation is correct statement because at temperature oil's physical as well as chemical property tend to change.
Hence, Tech B is correct and Tech A is incorrect.
Answer:
#_photon = 5 10²⁰ photons / s
Explanation:
For this exercise let's calculate the energy of a single quantum of energy, use Planck's law
E = h f
c= λ f
E = h c / λ
λ= 1000 nm (1 m / 109 nm) = 1000 10⁻⁹ m
Let's calculate
E₀ = 6.6310⁻³⁴ 3 10⁸/1000 10⁻⁹
E₀ = 19.89 10⁻²⁰ J
This is the energy emitted by a photon let's use a proportions rule to find the number emitted in P = 100 w
#_photon = P / E₀
#_photon = 100 / 19.89 10⁻²⁰
#_photon = 5 10²⁰ photons / s